Peptide nucleic acid structure

Dey S., Alpha Helical Peptide Nucleic Acids (Alpha PNAs) - Integration of Protein Structure and Nucleic Acid Function. PhD thesis. Case Western Reserve University, Cleveland, OH, January 2001. 

Shapiro (2000) draws our attention to another type of problem the homopolymer problem in biogenesis. Many biogenesis hypotheses presuppose the spontaneous formation of polymeric organic replicators which were formed from a mixture of inorganic compounds these replicators consist of subunits of a known chemical species. Their structure involves a backbone which is bonded to information-transmitting residues. As we shall discuss in Sect. 6.7, not only RNA and DNA, but also proteins and peptide nucleic acids (PNA) have been suggested as possible information transmitters. Shapiro rightly considers that until now, not... 

The term peptide nucleic acids was chosen because of the peptide bond in the polymer (see Sect. 5.2). The bond between the polyamide strand and the organic bases involves an acetyl group. The formation of DNA-like double helix structures by PNAs was described by Pernilla Wittung et al. (1994). The question arises as to whether peptide nucleic acids can in fact be synthesized under prebiotic conditions. 

The synthesis and crystal structure of the peptide nucleic acid (PNA) monomer 25 having cyanuric acid as nucleobase have been described. Monomer 25 can be directly used for the solid phase synthesis of PNA oligomers . 

Scheme 1 Structures of Peptide Nucleic Acid (Left) and DNA (Right)11 21 H2N...

Fig. 4.2.9. Linear PNA-beacons in unhybrid-ized peptide nucleic acids (PNA) the averaged distance between appropriately appended fluorescence donor and fluorescence quencher groups is smaller than in the duplex structure.

Figure 32 The structure and AFM image of a hybridized DNA on to peptide nucleic acid (PNA) attached SWNT. SWNT appear as bright light the paler strands represent bound DNA. Scale bar =100 mn. (Reprinted with permission from Ref. 217. 2002 Macmillan Magazines...

Most synthetic DNA analogs represent logical departures from the natural structure. However, one of the most radical structural modifications of DNA to appear in the literature is peptide nucleic acid (PNA, Fig. 1), in which the sugar-phosphate backbone is abolished entirely in favor of a pseudopeptide. PNA was first reported by Nielsen et al. in 1991... 

Fig. 1 Dinucleotide structures (as found in respective dino-cleotides). (A) morpholino analog (B) normal DNA or RNA (C) phosphorothioate analog of DNA (D) peptide nucleic acid.

Figure 122. Structure of peptide nucleic acids (PNAs) labeled with dihedral angles.

Figure 124. Crystal structure of a peptide nucleic acid duplex (left).901 For clarity, one strand is colored yellow and the other uses conventional atom colors PNA2-DNA triplex (right).710 Four chains are shown. The DNA chains are colored yellow and blue. The DNA sequence is 5 -(GAAGAAGAG)-3. The PNA chains are colored red and green. The PNA sequence is H2N- (CTCTTCTTC-His-Gly-Ser-Ser-Gly-His-CTTCTTCTC) -C02H.

Related to this work are also the investigations carried out on peptide nucleic acids (PNAs) which have recently been reviewed by Nielsen.39 PNAs are a new class of flexible oligomeric DNA analogues in which the base pairs are carried by a peptide backbone. When this backbone consists of cyclohexyl-derived amino acids, the molecules adopt a more rigid conformation and are able to also form a doublehelical structure.40... 

Structural preorganization of peptide nucleic acids with the formation of chiral cationic analogs with a five- or six-membered ring structure 02EJ02021. 

Structure, properties, application, strategy, and practice of chemical synthesis of peptide-nucleic acids 02UK81. 

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